Arthritis & Rheumatism, Volume 63,
November 2011 Abstract Supplement

Abstracts of the American College of
Rheumatology/Association of Rheumatology Health Professionals
Annual Scientific Meeting
Chicago, Illinois November 4-9, 2011.


Comparison of Cytokine Levels in the Synovial Joint Fluid Between Rapidly Destructive Coxopathy, Hip Osteoarthritis, Rheumatoid Arthritis, and Hip Oseteonecrosis.

Abe1,  Hirohito, Sakai1,  Takashi, Ando2,  Wataru, Takao1,  Masaki, Nishii1,  Takashi, Nakamura3,  Nobuo, Yoshikawa1,  Hideki

Osaka University Graduate School of Medicine, Suita, Osaka, Japan
Kansai Rousai Hospital, Amagasaki, Japan
Kyowakai Hospital, Suita, Japan

Background/Purpose:

Rapidly destructive coxopathy (RDC) represents destruction of the femoral head and/or acetabulum within 6 to 12 months mostly in elderly females. RDC causes severe hip pain and disabilities and results in total hip arthroplasty (THA). Several conditions have been suggested as the primary causes of RDC, including increasing pelvic posterior inclination as a mechanical factor, and high serum concentration of MMP-3, MMP-9 as biological factors. However, the cytokine levels of the synovial joint fluid with RDC and other hip diseases have not been well documented. The purpose of this study is to determine the characteristics of the cytokine levels compared between RDC, hip osteoarthritis (OA), rheumatoid arthritis (RA), and hip oseteonecrosis (ON) using synovial joint fluid collected during THA.

Methods:

56 hips in 55 patients were investigated in this study. The mean age was 67.3 years (range; 25 to 85 years). They consisted of 9 males and 46 females. There were 22 hips with RDC, 13 hips with OA, 6 hips with RA, and 15 hips with ON which were divided into 6 hips with collapsed ON and 9 hips with terminal ON. The diagnosis of RDC was done on plain radiographs or MRI of the hip, which showed diffuse low signal intensity area in the femoral head and neck on T1WI, and high signal intensity area on T2WI with or without rapidly destructive findings. All hips with RDC and terminal ON showed widespread obliteration of the joint space. The synovial joint fluid was collected during THA and was stored at -80°C. The cytokine levels including IL-1b, IL-6, IL-8, and TNF-a were measured by using Homogenous Time Resolved Fluorescense (HTRF). We compared the cytokine levels between hip diseases. In ON group, we also compared the cytokine level between the collapsed ON and the terminal ON to investigate the influence of the severity of joint destruction on the cytokine level. The statistical analysis was performed by Kruskal-Wallis test and Mann-Whitney U test. The level of significance was set at p<0.05.

Results:

The mean IL-8 level (pg/ml) was 3536±2678 in RDC, 1521±1319 in OA, 2171±1176 in RA, and 2885±3232 in ON, respectively. IL-8 level in RDC were significantly higher than that in OA (p=0.02). There were no differences in IL-1b and TNF-a between all the hip disease categories. IL-6 level (pg/ml) in the collapsed ON was significantly higher than that in the terminal ON (collapsed ON: 2478±2026 vs terminal ON: 707±708, p=0.03).

Conclusion:

There were few reports concerning the cytokine levels of the synovial joint fluid in hip diseases. In the present study, IL-8 levels were significantly higher in RDC hips. Although some studies had reported that knee with RA had significantly higher level of IL-8 than that with OA, there was no difference between RA and OA in the present study. Some studies have also reported that the severity of joint destruction had influenced on the Il-1b level of the joint fluid of the knee. In the ON group, IL-6 level in the collapsed ON was significantly higher than that in the terminal ON. The staging of the hip joint destruction have influenced on the cytokine level of the joint fluid of the hip. IL-8 in synovial joint fluid may be useful to diagnose the RDC.

To cite this abstract, please use the following information:
Abe, Hirohito, Sakai, Takashi, Ando, Wataru, Takao, Masaki, Nishii, Takashi, Nakamura, Nobuo, et al; Comparison of Cytokine Levels in the Synovial Joint Fluid Between Rapidly Destructive Coxopathy, Hip Osteoarthritis, Rheumatoid Arthritis, and Hip Oseteonecrosis. [abstract]. Arthritis Rheum 2011;63 Suppl 10 :1082
DOI:

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